Suppose you are working on a project where you need to create several beans with business logic, database interaction, and APIs. How would you use different annotations to organize and define these beans properly?
- @Component for beans, @Service for business logic, @Repository for database interaction, and @Controller for APIs.
- @Bean for all types of beans.
- @Entity for beans, @Data for business logic, @Service for database interaction, and @RestController for APIs.
- @Resource for all types of beans.
In a Spring Boot project, it's essential to use the appropriate annotations for proper organization. Use @Component for general beans, @Service for business logic, @Repository for database interaction, and @Controller for APIs. This ensures that beans are correctly categorized, leading to better code organization and maintainability. The other options either do not follow the recommended Spring Boot annotation conventions or mix them inappropriately.
How can cache be synchronized across multiple instances of a Spring Boot application in a distributed environment?
- Use a distributed cache solution like Redis or Hazelcast.
- Implement session sharing between instances using a common database.
- Manually replicate cache data across instances using REST APIs.
- Enable cache synchronization in Spring Boot properties.
To synchronize the cache across multiple instances of a Spring Boot application in a distributed environment, you can use a distributed cache solution like Redis or Hazelcast. These tools provide distributed caching capabilities that keep cache data consistent across instances. The other options do not provide a robust and efficient solution for cache synchronization in a distributed environment.
To test interactions with the database in isolation, Spring Boot provides the _____ annotation, which disables full auto-configuration and applies only JPA-related configurations.
- @DataJpaTest
- @EntityTest
- @SpringBootTest
- @WebMvcTest
The @DataJpaTest annotation in Spring Boot is used to test interactions with the database. It disables full auto-configuration and applies only JPA-related configurations, allowing you to focus on testing data access components.
The _____ annotation in JUnit is used to indicate that a method should be executed after all tests in the current test class have been run.
- @After
- @AfterAll
- @AfterClass
- @BeforeClass
In JUnit, the @AfterClass annotation is used to indicate that a method should be executed after all tests in the current test class have been run. This is often used for cleanup tasks after running a suite of tests.
When using the @WebMvcTest annotation in Spring Boot, only the _____ are typically loaded into the application context.
- configuration files
- controllers and related components
- entire application context
- service and repository beans
With @WebMvcTest, only the controllers and related components are typically loaded into the application context. This is useful for testing the web layer of your application in isolation without loading the entire context.
In Spring Boot, the _____ annotation can be used to specify the conditions or actions that should be executed before testing each method.
- @Before
- @BeforeAll
- @BeforeEach
- @BeforeMethod
In Spring Boot, you can use the @BeforeEach annotation to specify actions that should be executed before testing each method. This is often used for setup actions before individual test cases.
For integration testing in Spring Boot, the _____ annotation is used to specify that only certain parts or layers of the application should be loaded.
- @ContextConfiguration
- @IntegrationTest
- @SpringBootTest
- @WebMvcTest
In Spring Boot, to load only the web layer of an application during integration tests, you can use the @WebMvcTest annotation. It narrows down the scope of the context loaded for testing to just the web-related components.
In Spring Boot, which annotation is used to handle exceptions at the controller level?
- @ExceptionHandler
- @ControllerAdvice
- @RestController
- @RequestMapping
In Spring Boot, the @ExceptionHandler annotation is used to handle exceptions at the controller level. This annotation allows you to define methods within a controller that can handle specific exceptions thrown by that controller. The other options, such as @ControllerAdvice, @RestController, and @RequestMapping, have different roles and are not used for handling exceptions directly at the controller level.
In a Spring Boot test, how can you override the properties defined in the application.properties file?
- Create a new application-test.properties file.
- Use @TestPropertySource annotation to load custom properties.
- Modify application.properties directly in the test code.
- Properties cannot be overridden in Spring Boot tests.
In Spring Boot tests, you can override properties defined in application.properties by using the @TestPropertySource annotation to load custom properties. Option (1) is incorrect as it's not a standard practice. Option (3) is incorrect because modifying application.properties directly in test code is not recommended. Option (4) is incorrect; properties can be overridden.
How does Spring Boot support reactive programming in conjunction with traditional MVC patterns?
- By automatically adapting to the reactive or traditional approach based on the project's dependencies.
- By forcing developers to choose between reactive or traditional MVC, with no middle ground.
- By offering separate modules for reactive and traditional MVC development.
- By requiring developers to write complex custom adapters.
Spring Boot supports reactive programming in conjunction with traditional MVC patterns by automatically adapting to the reactive or traditional approach based on the project's dependencies. It uses conditional configuration and auto-detection of libraries to determine whether to configure the application as reactive or traditional. This allows developers to seamlessly integrate reactive and non-reactive components within the same application, providing flexibility and compatibility with both programming models.